Security systems are employed to detect changes in a monitored environment due to the intrusion of an entity, such as an unwanted human, animal or inanimate object. However, many security systems find it difficult to perform proper motion and change detection without being subjected to false alarms. Some of these alarms are due to normal changes to the setting, like moving curtains, changing airflow, automatic light switching, pests or other non-harmful entities entering the monitored background. Routinely, these events are made part of the background to minimize false alarms, but unfortunately, such action at the same time lowers the probability of detecting small changes like for example the placement of an electronic bug in the monitored environment.
Additionally, many security systems are easy to spoof. For example, systems that detect heat generated from a human body can be spoofed by a person wearing a large coat and moving slowly through a room. Also, these systems may not detect the entrance of an electronic robot, or other inanimate object entering the room. Laser beam type security systems can be spoofed using mirrors, or by avoiding the laser beams when moving through the room. Security systems that employ cameras can be spoofed by moving outside of the field of view of the cameras, or moving between objects blocking the field of view of the cameras.